PREGNANT women are not receiving the most effective screening tests for Down's Syndrome even though switching would not necessarily cost more, researchers said yesterday.

PREGNANT women are not receiving the most effective screening tests for Down's Syndrome even though switching would not necessarily cost more, researchers said yesterday.

Better screening methods would result in fewer Down's babies being born and fewer unaffected babies being lost through miscarriage, it was claimed.

About one in 600 births produces a child with Down's Syndrome, a genetic disorder which causes physical and mental handicap.

Women can choose to be screened for Down's Syndrome, which usually consists of a "double" test for two blood chemicals.

The researchers, led by Dr Stuart Logan at the Institute of Child Health in London, compared the outcome and cost of no screening with nine different screening strategies.

Writing in the British Medical Journal, they concluded that currently women were not being offered the best options.

Four screening tests not normally available on the NHS were more effective than using the "double" test which was estimated to cost around &#xA3;200,000 per 10,000 pregnant women.

Switching to a "quadruple" test which checked for four blood chemicals cost &#xA3;241,000 and a "first trimester combined" test &#xA3;238,000.

These two tests also resulted in 1.2 or

1.5 fewer affected liveborn babies for every 10,000 pregnancies.

A "nuchal translucency" ultrasound test was more effective than the "double" test, resulting in 0.3 fewer affected liveborn babies, and cost &#xA3;70,000 less.

The "integrated" test, consisting of an ultrasound and two separate blood tests, resulted in 2.3 fewer affected babies but at a higher cost of &#xA3;276,000.

Dr Logan said, "There's a big ethical issue about whether to screen or not. All we are saying is that if you should decide to screen, you may as well offer the best option possible."

But a spokeswoman for the Down's Syndrome Association said, "It is important that medical professionals do not fall into the trap of assuming what parents' wishes will be by stating - as in this case - that better testing will directly `result in fewer affected babies'.

"A test result is simply information and it is wrong to make assumptions about the final outcome - an outcome that should be decided by the parents ."